Atelomycterus marmoratus ( Bennett, 1830 )

Cabebe-Barnuevo, Roxanne, Penuela, Dianne Frances, Delloro Jr., Emmanuel S., Babaran, Ricardo P., Motomura, Hiroyuki & Malay, Maria Celia D., 2025, Cartilaginous fish diversity in the Western Visayas, Philippines, including two putative unidentified species and the first record of Carcharhinus plumbeus (Elasmobranchii: Carcharhiniformes: Carcharhinidae), Acta Ichthyologica et Piscatoria 55, pp. 51-75 : 51-75

Atelomycterus marmoratus ( Bennett, 1830)

IUCN standard name :: Coral Catshark Fig. 6 , Table 1

Material examined.

UPVMI 3129, 479 mm TL, female, fish landing sites, Sibunag, Guimaras Province, Philippines, longline, 23 November 2020, coll. M. Asgar.

Morphological description.

Body elongated, slender, and cylindrical. Head short, narrow, and slightly flattened from above. Eyes horizontally oval; spiracles small, situated just behind eyes. Snout short; tip blunt and slightly flattened from above. Mouth long, broadly ovate, with labial furrows extending on both upper and lower jaws. Nostrils large, usually covered by broad, triangular nasal flap extending to mouth. Teeth short, very sharp, tricuspid; central cusp twice length of cusplets on either side. Skin thick, covered with dermal denticles and very sharp to touch. Dorsal fins moderately small with concave posterior margins; first dorsal fin originating behind pelvic fins; second dorsal fin originating from midpoint of anal-fin base. Anal fins similar in shape to dorsal fins but smaller in size. Pectoral fins moderately large; posterior margin slightly convex. Pelvic fin smaller than pectoral fins. Caudal fin relatively short; posterior tip of upper lobe broad; lower lobe indistinct; ventral notch located near tip of upper lobe. Five small gill slits on both sides; last two gill slits situated just above pectoral-fin base.

Color of fresh specimen. Body brown, covered with white spots outlined in black; some spots merged into horizontal bars, notably around head area; underside white with small, faint, brown-black spots extending from the trunk area to caudal fin. Fin edges white with scattered, irregular white and brown-black spots.

Color of preserved specimen. Body brown; underside white. White spots scattered on the body and fins are still visible, but the black outlines have faded.

Distribution.

Indo – Pacific. Western Indian Ocean: Pakistan to southern India; western Pacific: Malaysia, Indonesia, New Guinea, Philippines, Taiwan, and southern China ( Human and Ebert 2022).

DNA barcode.

The COI sequence of 607 bp was submitted to GenBank under accession number OR 614478.

Conservation status.

Near Threatened

Remarks.

Atelomycterus marmoratus can reach a maximum total length of 700 mm ( Compagno and Niem 1998 b) and is commonly found in coral reef habitats. The depth range of A. marmoratus remains unclear, however, a specimen was recorded at a minimum depth of 40 m near Bolinao, Philippines ( Compagno and Niem 1998 b; Compagno et al. 2005). There have been reports of this species in Philippine waters, including Cavite, Cebu, Manila, Negros Occidental (Bacolod), Negros Oriental (Dumaguete), Palawan (Busuanga), Pangasinan (Bolinao), and Sulu (Jolo) ( Compagno et al. 2005; Gonzales 2013; Aquino et al. 2023).

The specimen collected for this study was identified as A. marmoratus based on its combined characteristics, including a slender body covered with bordered white spots, two equal-sized dorsal fins, and a long labial furrow. Atelomycterus erdmanni Fahmi et White, 2015 share similar characteristics with A. marmoratus in having white spots on dorsal and lateral surfaces. However, A. marmoratus can be distinguished by having more spots (vs. fewer spots in A. erdmanni ), as noted by Fahmi and White (2015). Although direct counts comparing the number of white spots between these two species were not provided, this study observed that the Philippine specimen has approximately five rows of white spots on dorsal view of the head (see Fig. 6 B ), while the head spots of A. erdmanni consist of about two rows ( Fahmi and White 2015, figs. 1, 2). This feature should be confirmed in a larger number of specimens, including those of varying sizes, to verify its consistency across the species. The morphological identification of the Philippine specimen as A. marmoratus is further supported by its COI data, as shown in the phylogenetic tree (Fig. 3 ), where the Philippine sequence clusters with that of A. marmoratus and is clearly separated from the sequence of A. erdmanni .

Figures

Figure 3. Maximum likelihood phylogenetic tree of partial COI sequences from chimaeras and sharks, constructed using the Kimura 2 - parameter model. Philippine sequences are identified by UPVMI voucher codes, with related genera color-coded. Bootstrap support values (1000 replicates) are shown at nodes, and the scale bar represents evolutionary distance in substitutions per site.

Figure 6. Atelomycterus marmoratus from Western Visayas, Philippines, UPVMI 3129, 479 mm TL. A body in lateral view B head in dorsal view C oronasal region.